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1: /* DSSKey.java -- 2: Copyright 2001, 2002, 2003, 2006 Free Software Foundation, Inc. 3: 4: This file is a part of GNU Classpath. 5: 6: GNU Classpath is free software; you can redistribute it and/or modify 7: it under the terms of the GNU General Public License as published by 8: the Free Software Foundation; either version 2 of the License, or (at 9: your option) any later version. 10: 11: GNU Classpath is distributed in the hope that it will be useful, but 12: WITHOUT ANY WARRANTY; without even the implied warranty of 13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14: General Public License for more details. 15: 16: You should have received a copy of the GNU General Public License 17: along with GNU Classpath; if not, write to the Free Software 18: Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 19: USA 20: 21: Linking this library statically or dynamically with other modules is 22: making a combined work based on this library. Thus, the terms and 23: conditions of the GNU General Public License cover the whole 24: combination. 25: 26: As a special exception, the copyright holders of this library give you 27: permission to link this library with independent modules to produce an 28: executable, regardless of the license terms of these independent 29: modules, and to copy and distribute the resulting executable under 30: terms of your choice, provided that you also meet, for each linked 31: independent module, the terms and conditions of the license of that 32: module. An independent module is a module which is not derived from 33: or based on this library. If you modify this library, you may extend 34: this exception to your version of the library, but you are not 35: obligated to do so. If you do not wish to do so, delete this 36: exception statement from your version. */ 37: 38: 39: package gnu.java.security.key.dss; 40: 41: import gnu.java.lang.CPStringBuilder; 42: 43: import gnu.java.security.Registry; 44: import gnu.java.security.action.GetPropertyAction; 45: import gnu.java.security.util.FormatUtil; 46: 47: import java.math.BigInteger; 48: import java.security.AccessController; 49: import java.security.Key; 50: import java.security.interfaces.DSAKey; 51: import java.security.interfaces.DSAParams; 52: import java.security.spec.DSAParameterSpec; 53: 54: /** 55: * A base asbtract class for both public and private DSS (Digital Signature 56: * Standard) keys. It encapsulates the three DSS numbers: <code>p</code>, 57: * <code>q</code> and <code>g</code>. 58: * <p> 59: * According to the JDK, cryptographic <i>Keys</i> all have a <i>format</i>. 60: * The format used in this implementation is called <i>Raw</i>, and basically 61: * consists of the raw byte sequences of algorithm parameters. The exact order 62: * of the byte sequences and the implementation details are given in each of the 63: * relevant <code>getEncoded()</code> methods of each of the private and 64: * public keys. 65: * <p> 66: * <b>IMPORTANT</b>: Under certain circumstances (e.g. in an X.509 certificate 67: * with inherited AlgorithmIdentifier's parameters of a SubjectPublicKeyInfo 68: * element) these three MPIs may be <code>null</code>. 69: * 70: * @see DSSPrivateKey#getEncoded 71: * @see DSSPublicKey#getEncoded 72: */ 73: public abstract class DSSKey 74: implements Key, DSAKey 75: { 76: /** 77: * A prime modulus, where 78: * <code>2<sup>L-1</sup> < p < 2<sup>L</sup></code> for 79: * <code>512 <= L <= 1024</code> and <code>L</code> a multiple of 80: * <code>64</code>. 81: */ 82: protected final BigInteger p; 83: 84: /** 85: * A prime divisor of <code>p - 1</code>, where 86: * <code>2<sup>159</sup> < q 87: * < 2<sup>160</sup></code>. 88: */ 89: protected final BigInteger q; 90: 91: /** 92: * <code>g = h<sup>(p-1)</sup>/q mod p</code>, where <code>h</code> is 93: * any integer with <code>1 < h < p - 1</code> such that <code>h<sup> 94: * (p-1)</sup>/q mod p > 1</code> (<code>g</code> 95: * has order <code>q mod p 96: * </code>). 97: */ 98: protected final BigInteger g; 99: 100: /** 101: * Identifier of the default encoding format to use when externalizing the key 102: * material. 103: */ 104: protected final int defaultFormat; 105: 106: /** String representation of this key. Cached for speed. */ 107: private transient String str; 108: 109: /** 110: * Trivial protected constructor. 111: * 112: * @param defaultFormat the identifier of the encoding format to use by 113: * default when externalizing the key. 114: * @param p the DSS parameter <code>p</code>. 115: * @param q the DSS parameter <code>q</code>. 116: * @param g the DSS parameter <code>g</code>. 117: */ 118: protected DSSKey(int defaultFormat, BigInteger p, BigInteger q, BigInteger g) 119: { 120: super(); 121: 122: this.defaultFormat = defaultFormat <= 0 ? Registry.RAW_ENCODING_ID 123: : defaultFormat; 124: this.p = p; 125: this.q = q; 126: this.g = g; 127: } 128: 129: public DSAParams getParams() 130: { 131: return new DSAParameterSpec(p, q, g); 132: } 133: 134: public String getAlgorithm() 135: { 136: return Registry.DSS_KPG; 137: } 138: 139: /** @deprecated see getEncoded(int). */ 140: public byte[] getEncoded() 141: { 142: return getEncoded(defaultFormat); 143: } 144: 145: public String getFormat() 146: { 147: return FormatUtil.getEncodingShortName(defaultFormat); 148: } 149: 150: /** 151: * Returns <code>true</code> if the designated object is an instance of 152: * {@link DSAKey} and has the same DSS (Digital Signature Standard) parameter 153: * values as this one. 154: * <p> 155: * Always returns <code>false</code> if the MPIs of this key are 156: * <i>inherited</i>. This may be the case when the key is re-constructed from 157: * an X.509 certificate with absent or NULL AlgorithmIdentifier's parameters 158: * field. 159: * 160: * @param obj the other non-null DSS key to compare to. 161: * @return <code>true</code> if the designated object is of the same type 162: * and value as this one. 163: */ 164: public boolean equals(Object obj) 165: { 166: if (hasInheritedParameters()) 167: return false; 168: 169: if (obj == null) 170: return false; 171: 172: if (! (obj instanceof DSAKey)) 173: return false; 174: 175: DSAKey that = (DSAKey) obj; 176: return p.equals(that.getParams().getP()) 177: && q.equals(that.getParams().getQ()) 178: && g.equals(that.getParams().getG()); 179: } 180: 181: public String toString() 182: { 183: if (str == null) 184: { 185: String ls = (String) AccessController.doPrivileged(new GetPropertyAction("line.separator")); 186: CPStringBuilder sb = new CPStringBuilder(ls) 187: .append("defaultFormat=").append(defaultFormat).append(",") 188: .append(ls); 189: if (hasInheritedParameters()) 190: sb.append("p=inherited,").append(ls) 191: .append("q=inherited,").append(ls) 192: .append("g=inherited"); 193: else 194: sb.append("p=0x").append(p.toString(16)).append(",").append(ls) 195: .append("q=0x").append(q.toString(16)).append(",").append(ls) 196: .append("g=0x").append(g.toString(16)); 197: str = sb.toString(); 198: } 199: return str; 200: } 201: 202: public abstract byte[] getEncoded(int format); 203: 204: /** 205: * @return <code>true</code> if <code>p</code>, <code>q</code> and 206: * <code>g</code> are all <code>null</code>. Returns 207: * <code>false</code> otherwise. 208: */ 209: public boolean hasInheritedParameters() 210: { 211: return p == null && q == null && g == null; 212: } 213: }